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Category Archives: Highway Engineering
Central Luzon Link Expressway (CLLEx)
The recently opened Central Luzon Link Expressway (CLLEx) is a freeway spanning the provinces of Tarlac and Nueva Ecija towards the Cagayan Valley side of Luzon. With the ends at Tarlac City, Tarlac and San Jose City, Nueva Ecija, Phase 1 currently terminates at Aliaga town; connecting to the Guimba-Aliaga Road. That is 18 kilometers of the planned 30.7 kilometers of the first phase, which is to end at Cabanatuan City, Nueva Ecija. Here are some photos taken by colleagues as they traveled to Tuguegarao this weekend.
Section of SCTEX leading to the junction where the road branches to either the TPLEX or the CLLEx. SCTEX is a tollway operated by Metro Pacific via its Manila North Tollways Corp. while TPLEX is a tollway operated by San Miguel Corp. CLLEx is currently a freeway under the DPWH.
SCTEX off-ramps to CLLEx (left) or Tarlac City (right)
The expressway currently has 2 lanes per direction plus shoulder along either direction. The median barrier is a post & rail semi-rigid structure.
Many of the traffic signs have yet to be installed
Not so much traffic along the freeway as shown in the photos. These were taken on a Sunday though and we wonder if there will be more vehicles during the weekdays.
As the freeway is still uncompleted, the end section in Nueva Ecija is two lane-two way with only cones and bollards separating opposing traffic.
Exit ramp towards the Guimba-Aliaga Road
There are no stops yet along the freeway. I am not aware if there is a timetable for it to become a tollway. Traffic is still quite low so perhaps making it a tollway will take some time as it might be difficult to have a profitable operation. It would be good to have it as a limited access freeway to establish demand and use for the road.
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Why do we keep widening roads?
I’m just going to share this article here. The article from The NY Times asks a question that has been bugging planners and engineers, particularly those who are in government and perhaps under the agencies like the DPWH, DOTr and NEDA. This also applies to planners, engineers and those from other disciplines involved in transportation infrastructure development and particularly roads or highways.
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On intersection treatments for bicycles
With the increasing popularity of bicycles as a mode of transport particularly for commuting (e.g., bike-to-work, bike-to-school), we should be redesigning our intersections to include elements essential for the safety of all users, whether on motorized or non-motorized modes. Here is a short but very informative article on how a simple intersection treatment can significantly improve safety for everyone especially cyclists and pedestrians:
Grief, N. (December 2, 2022) “How Green Paint Can Save Cyclists’ Lives,” Bicycling.com, https://www.bicycling.com/news/a42124210/bike-boxes-intersections/ [Last accessed: 12/3/2022]
To quote from the article:
“A bike box, on the other hand, seems to be the ideal middle ground and the option of the three that these researchers recommend. Cyclists feel more comfortable when compared to the free-for-all of a mixing zone because they have a designated area to be and they’re out ahead of vehicles, but according to the eye movement analysis, they remain alert and watchful for vehicles.”
Here are a couple of drawings showing bike boxes at intersections from the recent Bike Lanes Master Plan for Metro Manila, Metro Cebu and Metro Davao that was developed by DOTr with assistance from the UNDP:
Bike boxes on a typical three-leg intersection (DOTr and UNDP, 2022)
Bike boxes on a typical four-leg intersection (DOTr and UNDP, 2022)
The preceding drawings adhere to the DPWH design guidelines that mainly follow AASHTO Guidelines. Of course, there are other design references such as NACTO and the manuals of other countries (e.g., Netherlands, Australia, Singapore, etc.) were the best practice designs can be adopted for local applications.
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On emergency vehicles, speeds and road widths
I recall an online discussion about how roads need to be wide to accommodate emergency vehicles such as fire trucks/engines, ambulances and police vehicles. There are also videos shared on social media about how, with wide roads, motorists could move their vehicles to the sides to give way to emergency vehicles. These are used to support the argument that we need wide roads and that speeding for emergency vehicles is justified because of their purpose. The following article attempts to make a counter-argument:
Lewis, M. (November 21, 2022) “Ambulances vs. Pedestrians,” Planetizen, https://www.planetizen.com/blogs/119785-ambulances-vs-pedestrians [Last accessed: 11/24/2022]
To quote from the article:
“the “emergency response” argument in favor of wide streets only makes sense if the risk of death from a too-slow ambulance outweighs the risk of death from a speeding car.”
Certainly, the data on road crashes due to speeding should support the perception that there’s a higher risk of death from speeding vehicles compared to the risk of dying in relation to the emergency that’s supposedly being responded to. And in our country, perhaps this counter-argument is valid considering the “wang-wang” type of emergency vehicles moving about.
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The wide Roman Highway, Bataan
As it is National Heroes Day today, I thought it would be nice to feature a road in an area that witnessed the experiences and sacrifices of many heroes. I traveled to Bataan last July and took some photos of the roads there including the Roman Highway, which is the main corridor connecting many of the province’s major towns. Also called the Roman Superhighway, the highway originally had 2 lanes (bi-directional and undivided) with shoulders along both side of the road. Eventually, it was widened and extended to 4 lanes (2 per direction) with wide shoulders. The current Roman Highway has been expanded to 6 lanes with shoulders but for most parts appear to effectively have only 4 lanes and paved shoulders.
The wide Roman Highway does not carry much vehicular traffic
The road widening is not complete as most bridges have not been widened. These produce bottlenecks like the one in the photo where the additional lane is effectively relegated to a shoulder.
The highway is practically straight but presents many examples of sags and crests. For those into highway engineering, images like the ones I share in this post are textbook examples for sight distance topics.
Another sag vertical curve with a bridge near or at the lowest point in the sag. Again, notice that the additional lanes are currently discontinuous at the bridge and there’s a barrier (orange) to warn motorists and guide them back to the original carriageway.
The highway is used by many trucks as there are industrial centers located along the highway including the PNOC in Limay and what used to be called the Bataan Export Processing Zone (BEPZ now the Bataan Freeport) at the end of the highway in Mariveles.
The widening of the Roman Highway includes the addition of one lane per direction and a narrow shoulder just before the sidewalks. The shoulder could easily be configured into a bike lane but that third lane can easily be designated for bicycles considering the traffic is usually light at most sections of the highway.
A section where the bridge has already been widened features 3 wide lanes per direction. The shoulders are still there but are not included in the bridge.
LGUs are joining the No-Contact Apprehension bandwagon
Another view of the wide highway
More on Bataan roads in a future post. I also took photos of the Gov. J.J. Linao National Road (Pilar – Bagac Road), which is the main access road to the Mt. Samat Shrine.
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On asphalt overlays and opportunities to rationalize pavement markings
Entire road sections along my commuting routes have had recent asphalt overlays or are being prepared for it. This is part of the national government’s regular maintenance program for roads implemented by the Department of Public Works and Highways (DPWH).
Newly asphalted pavement along the eastbound section of Ortigas Avenue Extension – can you guess how many lanes will fit here?
The previous photo was taken one week ago. This is what the section looks like after the contractor restored the pavement markings. I say restore because these are practically the same 3 lanes prior to the asphalt overlay to the rigid pavement structure.
Pavement marking delineating the traffic lanes, median and gutter
I wonder if the DPWH included bike lanes when they contacted the asphalt overlay and pavement markings for this road. There was none before and the new overlay presented a blank slate to which Class III bike lanes could at least have been provided. There is already an increasing number of bike-to-work traffic along Ortigas Ave. Ext. and the Manila East Road, which connects the large towns of Rizal and serves as one of the major arterials connecting the Province of Rizal to Metro Manila (the other being Marcos Highway).
Asphalt overlays like this provide opportunities to rationalize road space through adjustments to the pavement markings. Granted that there’s significant bus and truck traffic along this road, it is still possible to allocate or at least delineate 1.5m to 2m for cyclists. That should also help in making motorists aware of bike traffic and in the long run influence behavior towards safer travels for all road users.
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Some old drawing tools for clothoids
I took some photos of old (vintage if you prefer) drawing tools that I have at our laboratory at the university. We found this in the storage many years ago and people seem to have forgotten about them. Instead of heading for storage or being forgotten or worse, thrown away, we decided to keep them at our laboratory mainly to show our students how certain highway or street curves were drawn in the ‘old days’. I am currently the custodian of this and another set that I have kept at my other office at the civil engineering building.
The wooden box is at my office at UP Diliman
The sign basically translates to clothoid drawing tools made by a company based in Setagaya in Tokyo. There are 14 instruments in the box for clothoid parameter values of A = 20m to 350m.
Opening the box shows slots holding instruments for drawing clothoids or spiral curves
Some of the instruments from the case – the large one on top is for A = 300m and 350m (scale 1:1000)
Comparison of size of instruments for (top) A = 60m and 65m, and (bottom) A = 30m and 35m (scale 1:1000)
Instrument for A = 30m and 35m (Scale 1:1000)
A protractor came along with the set but I assume other instruments such as a compass were used in drawing/drafting the curves.
I shall take photos of the other set when I get to visit the other office. These will be for records purposes as well as for posterity. These are practically museum pieces that are now perhaps rarely if even used.
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On roadway expansions and induced demand
We start December with another shared article. Here is another excellent article from Todd Litman about roadway expansions and induced demand:
Litman, T. (November 28, 2021) “The Roadway Expansion Paradox,” Planetizen.com, https://www.planetizen.com/blogs/115395-roadway-expansion-paradox?utm_source=newswire&utm_medium=email&utm_campaign=news-12022021&mc_cid=89cc0b2638&mc_eid=9ccfe464b1 [Last accessed: 12/3/2021]
Note the list of references at the end of the article for further reading.
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PAREX or PARES?
Much has already been written and said about the proposal by San Miguel Corporation (SMC) to build an elevated expressway atop (or along the banks) of the Pasig River. The project is called the Pasig River Expressway or PAREX. Although it has caught the attention of the public quite recently, the idea or concept is something that was already brought up and studies even before SMC took it up. I recall seeing this concept and even discussing about this with a close friend who was involved in modeling the traffic for an elevated highway along the Pasig River during the PNoy administration for the Metro Manila Development Authority (MMDA). The MMDA then was chaired by someone who is now a senator of the country. There was apparently no opposition then for this project that probably was dismissed or shelved as it had no takers at the time. Fast forward to the present and the concept was picked up or somehow fell into SMC. The latter did some work on it, pitched it to government and, one way or another, got it approved. Being a major project under a high profile company pitched to a government that went by its “build, build, build” slogan, it wasn’t so difficult to get this hyped.
Opposition to the PAREX comes from a broad mix of professionals, environmentalists and civil society groups who questioned not just the idea or concept but the process that led to government practically giving the green light for this project. Some have countered that perhaps, instead of PAREX there should be PARES. PARES would be a Pasig River Esplanade, inspired by the Iloilo River Esplanade. Maybe this is a better option. Maybe we could even have a tramline along the river if the ROW permits it. Or, perhaps instead of an elevated expressway (with the BRT and bike lane add-ons that were obviously included to soften the image of the tollway) there can be a elevated monorail along the Pasig River. This can be designed to have a minimal footprint and could certainly have branches such as one along the Marikina River. These two options alone provide alternatives that SMC should at least consider and study very well. The options might give the company a way to save face (literally and figuratively).
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Is it difficult to understand the phenomena of induced demand?
I’m sharing a recent article that laments about how transport departments in the US seemingly don’t understand the concept and phenomena of induced demand. Is it really difficult to understand or are transport officials including highway planners and engineers deliberately ignoring what’s staring them in the face?
Zipper, D. (September 28, 2021) “The Unstoppable Appeal of Highway Expansion,” Bloomberg City Lab, https://www.bloomberg.com/news/features/2021-09-28/why-widening-highways-doesn-t-bring-traffic-relief [Last accessed: 10/10/2021]
The topic in the article is very much applicable to our own Department of Public Works and Highways (DPWH). The DPWH’s key performance indicators (KPIs) need to change from the typical “kilometers of road constructed” or “lane-kilometers of roads widened” to something like “travel time between points A and B”. Agencies like the DPWH always like to claim they are for solving traffic congestion but we already know widening roads just won’t cut it. It has to be more comprehensive than that and involve the entire transport system rather than just a part (i.e., the road). And it has to be a collaborative effort with various other agencies like the Department of Transportation (DOTr) and local government units. Unfortunately, too, these agencies like the DOTr and those under it, and many (not all) LGUs also like to go at it solo so we end up with piecemeal solutions that are also often out of context.
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Caught (up) in traffic 